Infectious disease monitoring using location information and surveys

Abstract

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for automated contact tracing using multiple data sources. In some implementations, a system uses location data generated based on one or more types of signals, such as GPS signals, WI-FI signals, signals from cellular base stations, signals from short-range wireless technology (e.g., BLUETOOTH), and so on. The system also prompts users for information regarding their locations and the conditions present at the locations, either at the time a user is present or later. With this information, the system compares the tracked locations for different individuals to identify instances of contacts in which criteria for disease transmission potential are met, e.g., when two individuals have certain levels of proximity and timing. Detected instances of contacts can be used to inform individuals of exposure to a disease, as well as to notify public health authorities.

What is claimed is: 
     
       1. A method performed by one or more computers, the method comprising:
 receiving, by the one or more computers, location data from a device associated with a user, wherein the location data is based on a wireless signal received by the device; 
 determining, by the one or more computers, that a condition for prompting the user to provide information has been satisfied based on the location data, wherein determining that the condition is satisfied comprises identifying a gap in collected location data for the user or an inconsistency in collected location data for the user; 
 generating, by the one or more computers, data for a prompt to the user that requests user input to confirm or indicate a location of the user; 
 providing, by the one or more computers, the data for the prompt to the device associated with the user in response to determining that the condition has been satisfied; 
 receiving, by the one or more computers, user input provided in response to presentation of the prompt at the device associated with the user; 
 identifying, by the one or more computers, an instance of contact that is between the user and another person and that satisfies one or more criteria for disease transmission potential, wherein the instance of contact is identified based on the location data, the user input provided in response to the prompt, and location data for the person; and 
 based on information indicating that the user or the person has been identified as having a confirmed or probable infection of a disease, providing, by the one or more computers, a notification of the contact between the user and the person to the user, the person, and/or to a public health authority. 
 
     
     
       2. The method of  claim 1 , wherein the disease is COVID-19. 
     
     
       3. The method of  claim 1 , wherein the device associated with the user is a phone of the user or a wearable device of the user. 
     
     
       4. The method of  claim 1 , wherein receiving the location data comprises receiving, from the device associated with the user, location data provided over a communication network that indicates a particular location that is a current location of the device;
 wherein generating the data for the prompt to the user comprises generating one or more requests for information to confirm a presence of the user at the particular location or to indicate conditions at the particular location; 
 wherein providing the data for the prompt comprises providing the data for the prompt while the device is located at the particular location; and 
 wherein the method includes causing the device associated with the user to present, while the device is located at the particular location, the prompt or to provide a notification that informs the user of the prompt. 
 
     
     
       5. The method of  claim 4 , wherein the data for the prompt is sent at a time when neither the user nor the person has been identified yet as having a confirmed or probable infection with the disease. 
     
     
       6. The method of  claim 1 , wherein receiving the location data comprises receiving location data that indicates a current location of the device;
 wherein determining that the condition for prompting the user to provide information has been satisfied is based on:
 the current location or a location type of the current location satisfying one or more criteria; and 
 determining that the device associated with the user arrived at the location or remained at the location for at least a predetermined minimum duration of time. 
 
 
     
     
       7. The method of  claim 1 , wherein the location data indicates a location of the device associated with the user, wherein the location is a current location of the device or a previous location of the device; and
 wherein determining that the condition for prompting the user to provide information has been satisfied is based on determining, based on location data for the person, that the person was at the location either (i) concurrently with the presence of the device at the location or (ii) no more than a maximum amount of time prior to arrival of the device at the location. 
 
     
     
       8. The method of  claim 1 , wherein determining that the condition for prompting the user to provide information has been satisfied is based on data indicating that the user or the person has a confirmed or probable infection of the disease. 
     
     
       9. The method of  claim 1 , wherein the location data indicates a location of the user at a first time;
 wherein the method includes receiving, at a second time after the device associated with the user has left the location, additional data indicating that (i) the user or the person has been identified as having a confirmed or probable infection of a disease, or (ii) the person was located at the location at the same time as the user or there is no more than a maximum amount of time between the presence of the user at the location and the presence of the person at the location; 
 wherein determining that the condition for prompting the user to provide information has been satisfied is based on the additional data; and 
 wherein the data for the prompt is generated and provided after the device associated with the user has left the location. 
 
     
     
       10. The method of  claim 1 , comprising:
 identifying, based on location data for the user and location data for the person, an overlap in locations visited by the person and locations visited by the user; and 
 based on identifying overlap in locations visited by the person and locations visited by the user, sending data, to a second device associated with the person, for a second prompt requesting information regarding a location visited by both the user and the person; 
 wherein identifying the contact between the user and the person is further based on second user input provided by the person in response to presentation of the second prompt. 
 
     
     
       11. The method of  claim 1 , wherein the one or more criteria for disease transmission potential include one or more of:
 proximity of the user and the person; 
 a duration of time the person and the user spent in proximity of each other; or 
 an amount of time between departure of one of the user and the person and subsequent arrival of the other of the user and the person. 
 
     
     
       12. The method of  claim 1 , wherein identifying the instance of contact between the user and another person that satisfies one or more criteria for disease transmission potential comprises determining that the user and the other person were within a minimum level of proximity for at least a minimum amount of time. 
     
     
       13. The method of  claim 1 , wherein the location data is based on at least two of:
 GPS signals; 
 Wi-Fi signals; 
 short-range wireless signals from a mobile device or a location beacon; or 
 signals from one or more cellular base stations. 
 
     
     
       14. A system comprising:
 one or more computers; and 
 one or more computer-readable media storing instructions that, when executed by the one or more computers, cause the one or more computers to perform operations comprising:
 receiving, by the one or more computers, location data from a device associated with a user, wherein the location data is based on a wireless signal received by the device; 
 determining, by the one or more computers, that a condition for prompting the user to provide information has been satisfied based on the location data, wherein determining that the condition is satisfied comprises identifying a gap in collected location data for the user or an inconsistency in collected location data for the user; 
 generating, by the one or more computers, data for a prompt to the user that requests user input to confirm or indicate a location of the user; 
 providing, by the one or more computers, the data for the prompt to the device associated with the user in response to determining that the condition has been satisfied; 
 receiving, by the one or more computers, user input provided in response to presentation of the prompt at the device associated with the user; 
 identifying, by the one or more computers, an instance of contact between the user and another person that satisfies one or more criteria for disease transmission potential, wherein the instance of contact is identified based on the location data, the user input provided in response to the prompt, and location data for the person; and 
 based on information indicating that the user or the person has been identified as having a confirmed or probable infection of a disease, providing, by the one or more computers, a notification of the contact between the user and the person to the user, the person, and/or to a public health authority. 
 
 
     
     
       15. One or more non-transitory computer-readable media storing instructions that, when executed by one or more computers, cause the one or more computers to perform operations comprising:
 receiving, by the one or more computers, location data from a device associated with a user, wherein the location data is based on a wireless signal received by the device; 
 determining, by the one or more computers, that a condition for prompting the user to provide information has been satisfied based on the location data, wherein determining that the condition is satisfied comprises identifying a gap in collected location data for the user or an inconsistency in collected location data for the user; 
 generating, by the one or more computers, data for a prompt to the user that requests user input to confirm or indicate a location of the user; 
 providing, by the one or more computers, the data for the prompt to the device associated with the user in response to determining that the condition has been satisfied; 
 receiving, by the one or more computers, user input provided in response to presentation of the prompt at the device associated with the user; 
 identifying, by the one or more computers, an instance of contact between the user and another person that satisfies one or more criteria for disease transmission potential, wherein the instance of contact is identified based on the location data, the user input provided in response to the prompt, and location data for the person; and 
 based on information indicating that the user or the person has been identified as having a confirmed or probable infection of a disease, providing, by the one or more computers, a notification of the contact between the user and the person to the user, the person, and/or to a public health authority. 
 
     
     
       16. The method of  claim 1 , comprising accessing, by the one or more computers, stored condition data that indicates different conditions that are respectively satisfied by different properties of location data, wherein the different conditions are associated with different prompts;
 wherein the condition determined to be satisfied based on the location data for the user is one of the different conditions indicated by the stored condition data; and 
 wherein generating the prompt comprises selecting a prompt associated with the condition determined to be satisfied based on the location data for the user. 
 
     
     
       17. The method of  claim 1 , wherein the one or more computers are configured to automatically trigger presentation of different prompts to users selectively based on different conditions being detected for the users based on the location data for the users. 
     
     
       18. The method of  claim 1 , wherein determining that the condition is satisfied comprises detecting, based on the location data, proximity of the user to or arrival of the user at a location in a predetermined set of locations or at a location of a predetermined type. 
     
     
       19. The method of  claim 1 , wherein determining that the condition is satisfied comprises determining that the location data indicates a difference from previous behavior of the user or a difference from a behavior predicted using a predictive model.